Hydraulic coupling



Oct. 19, 1937. H. slNCLAlR 2,096,070

HYDRAULIC COUPLING Original Filed Oct. l, 1932 lugs INVENTOR HafodA52/clair BY Q W/Mvm ATTORNEYS Patented Oct.y 19, 1937 UNITED sTATEsPATENT OFFICE Original application October l, 1932, Serial No. 635,795,now Patent No. 2,074,348, dated March Divided and this application April9, 1935, Serial No. 15,502. In Great Britain October 6, 1931 z claims.(ci. soi-s4) 'Ihis application is a division of my application SerialNo. 635,795, flied Oct. 1, 1932, now Patent No. 2,074,346, granted March23, 1937.

The present invention relates to hydraulic cou- 5 plings or gears of thekinetic type wherein an annularv hydraulic circuit for the workingliquid is comprised by a driving impeller element co-axial with a drivenrunner element, the said two elements each comprising -a curved shellforming part of the boundary of the hydraulic circuit. It is' especiallybut not exclusively applicable to the type of coupling adapted tooperate with the hydraulic circuit only partly full of working liquid.

In order that such couplings and gears may be capable of transmittingpower with a high eiliciency, that is to say, with a low slip, it isnecessary to minimize losses due to churning of the working liquid andto the formation of eddies therein during its vortex circulation betweenthe driving and driven elements of the coupling. Consequently, inYcouplings adapted to operate at a high e'iciency, the several elementsforming the hydraulic circuit have been so shaped that the hydrauliccircuit is bounded by smooth owing lines, with the'result that thestream of working liquid, in circulating between the driving and drivenelements, is not subjected to abrupt deflection in its passage throughthe elements forming the hydraulic circuit.

High-efficiency couplings of the kind described above are often employedto connect driving and 'driven machines having a relatively highinertia,

and with such an arrangement it is known that, 3 if the relative speedof the driving and driven parts oi the coupling is rapidly varied (by,for

example, changing the ratio of a multi-ratio gearing connected in serieswith the hydraulic coupling), the torque transmitted by the coupling 40may momentarily rise to such a high value as to involve risk of damageto parts of the transmission system.

Furthermore, it has been found that, when such couplings are used withcertain kinds of power transmission systems under certain conditions ofoperation, violent iluctuations may occur in the value of the torquetransmitted by the coupling owing to inherent instability of the streamof liquid circulating between the driving ple, in one known arrangementof power transmission system, the coupling,v which is provided withmeans for varying the quantity of liquid in the hydraulic circuit whilethe coupling is operating, is connected between a driving maand drivenelements of the coupling. For examchine running at a substantiallyconstant. speed and a driven machinerequiring a high starting torque.With this arrangement, while the driving 'machine is rotating, thedriven machine may be started from rest by admitting liquid to 5 thehydraulic circuit, and the driven machine may be brought to rest byemptying or reducing the quantity of liquid in the hydraulic circuit. Itis found however, that when the driven machine has in this way beenaccelerated or re- 10 tarded, as the case may be, to a certain speed.the slip being high, torque surges may occur, so that it is not possibleto maintain stable conditions of speed of the driven element. The surgesmay also cause the driving machine to be heavily 15 overloaded,particularly if the inertia of the driven machine is high.

In another arrangement in which the coupling is employed to connect asource of power of vari- 1 able speed to a load requiring a highstarting 20 torque, it has been found that torque surges 'may occur whenthe Working chamber of the coupling is only partly lled, when the speedof the source'of power is relatively low and when the slip in thecoupling is high. 25

The torque surges above referred to are believed to be caused asfollows: When such a coupling is operating with a partly lled hydrauliccircuit and at a high slip, the circulation of the working liquid isirregular and indeterminate; 30 as the slip decreases, however, thecirculation assumes a definite form, for example, a shallow vortex ringof high velocity. This change in circulation occurs quickly and causes amore or less violent acceleration of the driven element, or 35conversely a more or less violent surge in power. The stream of liquidmay then become attenuated, being subjected to an increased centrifugalforce where it passes through the channels of the driven element, andthe circulation iinally 4 collapses, with the result that the torquefalls, and the slip increases again, so that the cycle may be repeated.

An object of the present invention is to provide an improved highelciency coupling of the 45 type described which is adaptedautomatically to prevent the transmission of undesirably high torqueduring acceleration orv deceleration of the load.

A further object is to provide such a coupling 50 in which the inherentinstability above referred to is eliminated or reduced to anunimportant. amount. y

According to the present invention, in a hydraulic coupling or` gear ofthe type hereinbefore an obstruction of suiiicient magnitude to preventthe attainment of an excessive velocity of circulation, and consequentlythe transmission of an undesirably high torque; and where the hydrauliccircuit is only partly filled with liquid the discontinuity serveseither to prevent the attainment oi' unstable ilow conditions or tolimit the magnitude of the instability to an unobjectionable value. r.

The invention will be described by way of example with reference to theaccompanying drawing, which shows diagrammatically two forms ofhydraulic coupling of the Vulcan (or so-called -.Fttinger) type and inwhich Fig. l is a sectional side elevation of part of one form ofimproved coupling.

Fig. 2 is an end view of a detail of the arrangement shown in Fig. 1taken on 'the line 2 2 `in that figure. f

Fig. 3 is a sectional side elevation of a further form of coupling takenon the line 3--3 of Fig. 4 and A Fig. 4 is a sectional end elevation ofa portion of this coupling taken on the line 4 4 in Fig. 3.

Referring to Figs. 1 and 2, the impeller element 3c is attached to thedriving shaft i, while the runner element lc is attached to the drivenshaft 2. A casing member 5b which vembraces the shell of the runnerelement 4c is secured to the periphery of the impeller 3c, formingtherewith a working chamber for the coupling liquid.'

'Ihe impeller is provided with alternate long and short vanes 1 and 6respectively, integral with the shell, and these vanes support a coreguide member l0. The runner is provided with vanes 8a supporting a coreguide member ii. Liquid inlet ports i2d are formed through the boss ofthe impeller, and discharge ports ila, which may be controlled in knownmanner by a ring valve 33,' serve to exhaust working liquid from theworking chamber. A valve i4 in a pipe supplyingA working liquid undera'suitable pressure controls the rate of inilow of liquid to the workingchamber. A stationary liquid supply sleeve 30a surrounds the drivingshaft I,liquid being admitted through the inlet valve il, the annularpassage Jia, the axial passage 32a, and inlet ports i2d. The boss 6I of\therimner Ic forms a cylindrical bearing for an axially movable portion61 ofthe runner, this movable portion including a shell 62 and vanes 63in line with vanes 8a of the runner 4c. 'I'he centre of the impeller 3cis cut back to form a space Si providing clearance for axial movement ofthe member 81. A plurality, for example three, spindles 64 formed withlongpitch screws are threaded through tapped holes in the member 61 andjournalled at 0i in the runner 4c in such a way as to be incapable oimoving axially therein. Relatively heavy blades 66 are pinned to thespindles 6I and are accommodated in the space between the shell of therunner 4c and the casing lb.

'I'he operation of this coupling is as follows.

and iZa.

When the coupling is operating at low slip and consequently the runner4c is rotating at a relatively high speed, centrifugal force due to therotation of this element holds the blades 6I in the radial directiondenoted by A in Fig. 2 and consequently the liquid pes through therunner have a smooth boundary. It has been proved experimentally that.when the liquid content of the working chamber isreduced and the slip ishigh, the action of centrifugal force, due to the higher velocity withwhich liquid now circulates between the impeller and the runner, urgesliquid out of the hydraulic circuit into the space accommodating f theblades 86, so that these blades remainv at least partly submerged. Owingto the increased slip, liquid carried round by the casing 5b impinges onthe blades 66 and rotates these blades and the spindles 64 towards theposition denoted by B. 'I'he rotation of the spindles 64 serves to movethe member B1 axially into the clearance space 6i formed on 4the im,peller 3c, so that the shell 82 now projects into the passages throughthe runner and thereby introduces a discontinuity in the contour of thiselement. If the slip decreases, centrifugal force acting on the blades6B overcomes the hydraulic force acting on them and the blades areconsequently rotated to position A, so that the smooth boundary of theliquid passages in the runner is restored. I

In the arrangement shown in Figs. 3 and 4 the runner le, which `iscovered by the casing 5a, is provided with alternate long and shortvanes 9 and 8, and in this case the stationary liquid supply sleeve 30embraces the driven shaft 2, the liquid inlet passages being denoted by32 The discontinuity is introduced yby means of blades 80, each ofwhichis supported on two rods i'slidably carried in bearings 92 formed on thecore guide member iib. the ar-V rangement being such that the blades caneither project into the working circuit or be withdrawn clear thereofinto a recess 96 formed on the radially outer part of the runner le. Therods 9i are urged towards the axis of the rotation of the couplingbysprings 93 compressed between the outer portion of the core guide liband collars 94 retained by cotter pins 95 on the rods 9i.v

In this arrangement, when the slip is high and the speed of the runneris consequently low. the force exerted by the springs ll overcomescentrifugal force due to the rotation of the runner and the blades arethereby caused to project partly over the inlet ends of the liquidpassages through the runner. As the slip in the coupling decreases, forexample owing to increaseL of liquid content in the working chamber,centrifugal force overcomes the force due to the springs, and the blades90 are thus withdrawn into the clearance space 96 and out of the path ofliquid flowing betwee the impeller and runner elements. i

'I'he invention may obviously be applied also to hydraulic gears, thatis to say, hydro-kinetic transmission devices wherein the hydrauliccir,- cuit includes a iixedreaction member and which therefore effect achange of torque as between the driving and driven shafts.

I claim: l l

l. A hydraulic coupling, or gear, of the kinetic type, comprising anannular hydraulic working circuit, means operable for impeding theliquid vortex circulation insaid working circuit, and means adapted tofunction in response to variation in slip in said coupling or gear forautomatically operating said means for impeding the vortex circulation.

2. A hydraulic coupling of the kinetic type,

' comprising a rotatable impeller element, a rotatable runner element,an annular hydraulic working circuit including said elements, liquidtransfer means for increasing and reducing the liquid content of saidcircuit while the coupling is operating. means operable for impeding theliquid vortex circulation in said working circuit, and means adaptedautomaticalLv to operate said means for impeding the circulation inresponse to variation in the speed of rotation of said runner element.

3. A hydraulic coupling, or gear, oi the kinetic type, comprisingrotatable impeller and runner elements, an annular 'hydraulic workingcircuit' including-said elements, means operable for introducing adiscontinuity into the boundary of said working circuit, and a membermounted for rotation with said runner element andV adapted to bedisplaced with respect to said runner element through the agency oi.'kinetic energy imparted to the working liquid by said impeller element,displacement of said member serving to operate said means forintroducing discontinuity into said boundary.

4. A hydraulic coupling of the kinetic type comprising a rotatableimpeller element, a rotatable runner element coaxial with said impellerelement, said elements having each an annular dished shell and beingjuxtaposed to form a toroidal working circuit, a movable baille capable`of forming a discontinuity in the boundary of said circuit, and meansmounted on said runner element for rotation therewith, operatively.connected with said baille and operating automatically in response toincrease in centrifugal force due to increase in speed of said runnerelement, for decreasing the magnitude of said discontinuity.

5. A hydraulic coupling, or gear, of the kinetic type comprising anannular hydraulic working circuit including rotatable co-axial impellerand runner members, means displaceable in an axial direction forintroducing a discontinuity into said Working circuit, and means adaptedto function in response to variation in slip that occurs in saidcoupling or gear for automatically displacing .said means forintroducing discontinuity into said working circuit.

comprising rotatable impeller and runner elements, an annularhydraulicworking circuit including said elements, and means, operableautomatically in response to variation in the slip that occurs in thecoupling, for impeding the circulation in said working circuit.

7. A hydraulic coupling of the kinetic type comprising a rotatableimpeller element, a rotatable runner eleinent co-axial with andjuxtaposed to said impeller element to form therewith an annularhydraulic working circuit, and an annular member which is movable in adirection parallel to the axis of said elements and which is operableautomatically in response to1 variation in the relative speed of saidelements, for impeding the circulation in said circuit when saidrelative s'peed is high.

8. A hydraulic coupling of the kinetic type comprising rotatableimpeller and runner elements. an annular hydraulic working circuitincluding said elements, and a baille element displaceable axially ofsaid elements so as to obstruct said cir- -cuit to a. variable extent,said baille element being mounted for rotation with one of said elementsand operable through the agency of energy imparted to the working liquidby said impeller element.

9. A hydraulic coupling of the kinetic type comprising a rotatableimpeller element and a rotatable runner element, each of said elementshaving an annular dished shell and said shells being juxtaposed to forman annular hydraulic working circuit, and a bame element movableautomatically in response to variation in the slip in said coupling.said baille element being so shaped that in one position it formssubstantially a continuation of the surfaceof one of said shells, and inanother position it projects into said circuit.

, 10. A hydraulic coupling of the kinetic type comprising a rotatableimpeller element, a rotatable runner element coaxial with said impellerelement, said elements having each an annular dished shell, and beingjuxtaposed to form a toroidal working circuit, a baille movable into andout of said circuit so as to impede to a variable extent the circulationof liquid in said circuit, and spring means arranged to urge said baillecontinuously into its operative position in said circuit, said baillebeing so mounted on said runner element that it is urged into itsinoperative position by centrifugal force due to rotation of said runnerelement.

11. A hydraulic coupling of the kinetic type comprising rotatabledriving and driven elements together forming an annular hydraulicworking circuit, means' for increasing and reducing the liquid contentof said circuit while said driving element is rotating, and a bailleelement operatively connected with a control spring and capable ofmoving automatically into and out of said circuitrin response tovariation in speed of said driven element.

12. Ahydraulic coupling of the kinetic typ comprising rotatable drivingand driven elements together forming an annular hydraulic workingcircuit, means for increasing and reducing the liquid content of saidcircuit while said driving element is rotating. and a spring-loadedbaille element mounted on said driven element and capable" of beingdisplaced into said circuit in response to increase in speed of saiddriven element. Y

' 13. A hydraulic coupling of the kinetic type comprising a rotatablevaned element, a second rotatable vaned element juxtaposed to said rstvaned element and forming therewith an annular hydraulic workingcircuit, a casing member ilxed to said iirst vaned element and coveringthe back of said second vaned element so as to form a chamber betweensaid casing and saidsecond vaned element, a bale member movable into andout of said circuit, and means mounted on the back of said second vanedelement, soshaped as to engage liquid adjacent to said shell, andcapable of automatically moving said baille into said circuit as aresult of an increase in the relative speed of rotation of said shelland said second vaned element.

14. A hydraulic coupling of the kinetic type comprising a rotatablevaned element, a second rotatable yaned element forming with said rstvaned element an annular working circuit, an

ment, and-a baille displaceable into and out of said circuit, said bladebeing operativelyv connected with said baille and serving automaticallyto displace said baille, in response to variation in relative speed ofsaid vaned elements.

15. A hydraulic coupling of the kinetic type, comprising a vanedimpeller element, a vaned runner element forming with said impellerelement an annular Working circuit, a casing fixed to the periphery ofsaid impeller element and covering the back of said runner element so asto form a chamber between said casing and said runner element, saidchamber being in communication with said circuit so that it is capableof receiving working liquid while the coupling is operating, a baillemember movable into and out of said circuit, a blade pivotally mountedon said l' runner element and so arranged as to engage liquid in saidchamber, and an operative connection between said blade and said baillemember whereby pivotal movement of said blade serves to actuate saidbarile member.

16. A hydraulic coupling of the kinetic type comprising a rotatablevaned element, a second rotatable vaned element forming with said firstvaned element an annular working circuit, an annular element iixed tosaid first vaned element and so shaped as to be capable of containingliquid while the coupling is operating, a blade capable of being engagedbyl liquid contained by said annular; element, said blade beingpivotally mounted on said second vanedelement so as to be capable ofdisplacement about an axis disposed longitudinally of the coupling, abaille movable parallel to said axis into and out of said circuitthrough the agency of co-operating screwthreaded parts, said blade beingoperatively connected with one of said parts.

17. A hydraulic coupling ofthe kinetic type having a vaned impellerelement, a vaned runner element, a hydraulic circuit including saidelements, a baille'mounted on said runner element and movable into andout of said circuit in a direction having a radial component about theaxis of rotation of said elements, and means serving to urge said bailletowards said axis.

18. A hydraulic coupling of the kinetic type, comprising a rotatableimpeller element, a rotatable runner element, said elements formingtogether an annular hydraulic working circuit, a baille member movableinto said circuit for yimpeding the liquid vortex circulationtherein,land means serving automatically to move said baiile member into saidcircuit in consequence of a reduction in speed of rotation of saidrunnery element while the speed of said impeller element remainsconstant. t

19. A hydraulic coupling of the kinetic type, comprising a rotatableimpeller element, a rotatable runner element, said elements formingtogether an annular hydraulic working circuit, a baille member movableinto said circuit for impeding the liquid vortex circulation therein,and means serving automatically to move said baille member intosaidcircuit in consequence of an increase in slit between said elementsinvolving a reduction in speed of rotation of said runner element.

working circuit while the coupling is operating,

`ments, an annular hydraulic working circuit including said elements,meansl operable'forv increasing and reducing the liquid contentof saidcircuit while the coupling is operating, and means.

operable automatically in response to variationin centrifugal force dueto change of speed of said runner element, for obstructing to a variablebut comparatively small extent the Iree circulation of the liquid insaid working circuit.

22. A hydraulic coupling of the kinetic type comprising a rotatableimpeller element, a rotatable -runner element coaxial with said impellerelement, said elements having each an annularly dished shell and beingjuxtaposed to form a toroidal working circuit, a baille movable into andout of said circuit, and actuating means mounted for rotation with saidrunner element', and movable at least in part radially with respect tothe axis of said elements, said actuating means being operativelyconnected with said baille in such manner that when said actuating meansmove away from said axis, said baiile is constrained to move towards itstion out of said circuit. y

23. A hydraulic coupling of the kinetic type comprising a rotatableimpeller element, a rotatable runner element coaxial with said impellerelement, said elements having each an annularly dished shell, and beingjuxtaposed to form a toroidal working circuit, and automatic controlmeans mounted for rotation with said runner element, said meansincluding a baille movable into and out of said circuit, and a memberwhich is displaceable in a direction having a component radial withrespect to the axis of said elements and which is operatively connectedto said baille, an outward movement of said member underthe iniluence ofincreasing centrifugal force' constraining said baille to move into itsinoperative position out of said circuit.

24. A hydraulic coupling of the kinetic type comprising a rotatableimpeller element, a rotatable runner element coaxial with said impellerelement, said elementsfhaving each an annular dished shell, and beingjuxtaposed to form a toroidal working circuit, and automatic control`means which are mounted for rotationiwith said runner element and whichinclude an actuating element movable towards and away from the axis ofsaid runner element, means urging said actuating element towards saidaxis, a baille movable into said circuit, and an operative connectionbetween said actuating means and said baille, constraining said baie tomove out of said circuit when said actuating means are forced away fromsaid axis by centrifugal force.

25. A hydraulic coupling of the kinetic type comprising an annularhydraulic Working circuit having a boundary following smooth flowinglines, means for varying the liquid content of said working circuitwhile the coupling is operating, and means responsive to variation inliquid content of said coupling for employing the energy of motion ofliquid within the coupling to introduce into said smooth boundary adiscontinuity adapted to impede the liquid vortex circulation in saidworking circuit.

HAROLD SINCLAIR.

inoperative posi-

